In recent years, research has been done on a system that connects a plurality of distributed power sources, such as solar cells and fuel cells, as power generation apparatuses and supplies power generated by the power generation apparatuses. The power generation apparatuses used as these distributed power sources for example include fuel cells such as a Polymer Electrolyte Fuel Cell (PEFC) and a Solid Oxide Fuel Cell (SOFC). A system that uses a plurality of such fuel cells as distributed power sources has also been proposed.
For example, a system for parallel operation of a plurality of distributed power sources including a plurality of fuel cell units has been proposed (for example, see JP 2007-194137 A (PTL 1)). The system disclosed in PLT 1 stores the power generation amount at the time of rated operation for each of the plurality of fuel cells and calculates the total power generation amount by totaling the power generation amounts at the time of rated operation for the fuel cells determined to be currently driven.